Brass nozzle V6. Read more about different nozzle diameters and their usage at PrusaPrinters.org. How to identify different nozzle sizes Note: V6 style nozzles can be installed on the Original Prusa MK4 and XL 3D printers with the Nextruder V6 Nozzle Adapter (sold separately). This product includes: Nozzle V6 (1 pcs) Specifications: Material: Brass Read more about different nozzle diameters and their usage at blog.prusa3d.com. To correctly install this replacement part, visit our knowledge base at help.prusa3d.com, select your specific printer model, and follow the instructions provided in the repair manual.